1. Field of Invention
The present invention relates to a method for and an apparatus for diagnosing a sound source and a vibration source, and more particularly to a method for and an apparatus for diagnosing a sound source and a vibration source which, in a transmitting system in which one or a plurality of sound sources or vibration sources constitute causes of sounds or vibrations at an evaluation point, make it possible to visually and quantitatively diagnose the sound sources or vibration sources contributing largely to the evaluation point, and can be used in making effective improvements.
2. Description of Related Art
Conventionally, as a method of analyzing the contribution of sound sources or vibration sources to an evaluation point, a method has been proposed in which, in a frequency domain, correlational components are determined from a transfer function between the respective sound sources or vibration sources and the evaluation point, and the rates of contribution of the sound sources or vibration sources to the evaluation point are determined from these correlational components.
Further, in recent years, a technique has been proposed for diagnosing the contribution of sound sources or vibration sources by using adaptive digital filters in a time domain (Japanese Patent Application Laid-Open No. 526722).
However, with the above-described conventional method of analyzing contribution in the frequency domain, only amplitude information is used, and phase information is not considered. Therefore, if there are strong correlations among inputs, analysis becomes difficult. In addition, it takes time in analysis, so that it is impossible to obtain results instantly, and steady data for a long time is required.
On the other hand, with the above-described conventional method of analyzing contribution in the time domain, analysis in operating conditions, i.e., in real time, becomes possible. In consequence, however, only the time waveform is obtained, and since the rates of contribution are evaluated from the magnitude of the amplitude of the time waveform, it is possible to determine only qualitative and approximate rates of contribution although they are determined in real time. Thus, there is a problem in that it is impossible to evaluate the degrees of instantaneous, quantitative contribution (contribution rates).